The present invention relates generally to regulating check valves and more specifically to an isolation and regulator valve for use in a lubrication system of an outboard marine engine.
Typically, two-stroke outboard marine engines did not have a separate oiling system. That is, these prior art engines required pre-mixing lubricant and fuel so that the lubricant dissolves in the fuel to lubricate the engine. This required consistent, accurate measuring and agitation of the mixture. There are many disadvantages to the prior art system of pre-mixing lubricant and fuel. For example, since various two-stroke engines require different mix concentrations, many outboard marine engine owners who also own other two-stroke engine equipment, such as various lawn and garden equipment and ATV""s, may store several different concentrations of oil/fuel mixture. This is not only an aggravation to the owner, but is also problematic if the containers become mixed up and the owner uses the wrong concentration for a particular two-stroke engine. While this is not catastrophic, if run over time with the wrong concentration, a two-stroke engine wears excessively.
The present invention is for use in a unique lubrication system for two-stroke engines. Such a lubrication system must provide lubrication to the fuel system to properly lubricate the fuel metering and injection system. However, it is important to prevent the backflow of any fuel from the fuel system back to the lubrication system so that fuel does not replace the lubricant in the lubrication system. It is also important to regulate the flow of lubricant into the fuel so that neither too much lubricant nor too little lubricant is added.
An additional problem in using an in-line check valve is the improper installation. If the check valve is installed backward, the flow of oil will be completely blocked which could destroy the engine.
It would therefore be advantageous to have a self-correcting valve that allows for a fool-proof installation. It would also be desirable to have a simple and inexpensive system and method of connecting a lubrication system to the fuel system of an outboard marine engine so that pre-mixing is unnecessary, backflow does not occur, and lubrication regulation is possible.
The present invention provides a system for lubricating fuel in an outboard marine engine so that pre-mixing of fuel and lubricant is not required. The present invention also provides a means for preventing fuel from entering the lubrication system. An improved device for lubricating fuel at a controlled rate is also disclosed. Further, the present invention provides a valve that does not allow reverse installation in the oil distribution system.
In accordance with one aspect of the invention, a lubrication system is provided upstream from a fuel system. An isolation check valve is positioned between the lubrication system and the fuel system. The isolation check valve contains a check ball biased by a spring so that when the lubricant pressure is great enough, the spring compresses and lubricant is allowed to flow around the check ball. The spring forces the ball back into its normally closed position as soon as the pressure is reduced after sufficient oil is allowed to pass, thus preventing the flow of fuel backwards into the lubricant system.
In accordance with another aspect of the invention, the isolation check valve has a regulating nozzle from which the lubricant is released. The regulating nozzle controls and injects the amount of lubricant into the fuel system. Rather than achieving this end with electrical means, the regulation of lubricant occurs because of the shape of the nozzle and the bias pressure on the check ball. The interior of the distal end of the isolation valve has a frusto-conical shape to assist in injecting the lubricant. Thus, not only does the nozzle provide the advantage of regulation of lubricant into the fuel system, it does so without the complexity and expense of an electrical system and with the simplicity of a check valve in a uniquely designed housing without additional moving parts to break or wear down.
Another feature of the present invention which adds to its simplicity and cost-efficiency is that installation of the isolating valve is self-correcting or xe2x80x9cfoolproof.xe2x80x9d The relative sizes of the hoses used in relation to the inlet and outlet construction of the valve does not allow the valve to be installed backwards. This prevents incorrect installation of the valve which would actually prevent the lubricant from reaching the fuel system and encourage fuel to enter the lubricant system, two actions which are antithetical to the objectives of this invention.
The present invention is further enhanced by the particular hoses used in connecting the lubricant system to the isolation valve and the isolation valve to the fuel system. It is advantageous for an owner or operator of an outboard marine engine to visualize lubricant passing into the fuel system in order to ensure that the lubricant system is functioning correctly. A semi-transparent hose can be employed to allow visualization. The present system allows the use of a semi-transparent hose only between the lubricant source and the isolation valve rather than the full distance from the lubricant source to the fuel source. The hose connecting the isolation valve to the fuel system may be a hose designed exclusively for fuel to avoid the rapid deterioration of a semi-transparent hose and thus reducing the overall cost of the system.
The hoses connected with the isolating check valve are attached firmly but are releasable in the event that the isolation valve must be removed for some reason. The hose at the regulating nozzle end of the valve is retained on the valve by a set of barbs, while the hose at the inlet end of the valve is retained by insertion into a push-to-connect fitting. The hose retained by barbs can be pulled away from the isolating check valve with some effort but will not fall off in the normal course of events. The hose retained by the push-to-connect fitting cannot be pulled from the fitting by hand unless a release mechanism on the fitting is depressed. The valve is thus kept firmly in its correct position without being permanently attached.
Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.